Cam forming machine



June l2, 1951 c. G. WRIGHT ET AL CAM FORMING MACHINE 4 Sheets-Sheet 1 Filed Aug. 3l, 1946 INVENTOR.

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, ,l Afm/ws? June 12, 1951 c. G. WRIGHT v-f-:T AL 2,557,043

CAM FORMING MACHINE Filed Aug. B1, 194e 4 sheets-Sheena NVENTOR. C/ayh G Ww'y/rt @vene C nomas* ATTORNEY June 12A, 1951 C. G. WRIGHT ET AL CAM FORMING MACHINE Filed Aug. 31, 194e 4 Sheets-Sheet 5 IN VEN TOR. /Q, zz., a mfr/741.#

Gene C "72am a s AT;0/PNEY June 12, 1951 c. G. WRIGHT ET AL 2,557,043

CAM FORMING MACHINE Filed Aug. 51, 194e 4 Sheets-Sheet 4 we E lll (l l; /M

46 FLQY INVEN TOR.

. 6e" e om as ,y Arra/P/vgy Patented June 12, d1951 CAM FORMING MACHINE Clayton G. Wright and Gene C. Thomas, Birmingham, Ala., assgnors to Continental Gin Company, a corporation of Delaware Application August 31, 1946, Serial No. 694,200

3 Claims.

This invention relates to a cam forming machine and has for its object the provision of apparatus of the character designated which shall Ybe adapted to produce `a master cam from a model cam and by a simple interchange of the tools, andthe interchange of a cam blank for the model cam to reproduce cams accurately in close approximation to the model vcam employed.

Another object of our invention is to provide a machine in which an intaglio master cam and a cam blank are mounted on a common swinging shaft and in which a feeler element bears against the master cam on one side of the shaft and a forming tool against the cam blank on the diametrically opposed side of the swinging shaft.

A further object of our invention is to provide a camgrinding machine 'in which a master cam is mounted upon a swinging shaft and by means of which the angularity of `motion of the swinging shaft is compensated.

A more specific object of our invention is to provide a cam forming machine .in which a plurality of master cams are mounted upon a single shaft in a swinging frame together with selector means for engaging the master cams.

Briefly, our improved apparatus preferably is in the form of an attachment for a lathe, for convenienoe in driving, and embodies a frame with a base having longitudinal grooves therein tting over the ways of the lathe. A swinging frame is suspended in the main frame and has a master cam shaft removably journalled therein which may be driven from the head stock of the lathe by means of a universal coupling permitting angularity of movement Vof the swinging frame. In form-ing master cams, a selected model cam is mounted on the outer end of the shaft and a master cam blank on the master cam shaft. In laying out the master cam, a suitable feeler is placed in the tool post of the lathe in engagement with the model cam and, as ythe shaft is rotated, a scribing roller is brought into association with the master cam blank and the master cam is scribed. After being scribed, the master cam is preferably removed from the machine and is cut to a rough outline. A grinding wheel is then substituted for the soribing disc and the master cam shaft is rotated by power. The feeler is held in engagement with the model cam until the master cam is ground to the proper form. When this has been done, a roller is substituted for the grinding wheel, and a cutting tool for the cam feeler. -A'cam blank then replaces the model cam and the roller bearing against the master cam holds the cutting tool lin engagement with'the cam blank to 'out it to the proper contour. The master-cam is held in engagement with the roller by means of a spring. lThe master 4cam `shaft-is adapted for holding a plural-ity of master'cams and there is provided selector mechanisrnwhereby any one of the selected master cams may be engaged by the lroller to hold the cutting tool in engagement with va Asuitable-cam blank.

All 'of the foregoing 'features and others which will become apparent from this specification are illustrated in the accompanying drawings, forming a part hereof, wherein AFig. lis an end elevation, partly in section and with certain parts broken away, showing my improved apparatus mounted on'a lathe bed;

Fig. 2 is a plan view thereof;

Fig. 3 is a front elevational view;

Fig. 4 is a plan view drawn toa reduced scale showing, the lapparatus mounted on a lat'h'e;

Fig. 5 is a diagrammatic view lshowing the 'manner of laying out'a master cam;

Fig. 6 is 'a Adiagrammatic sectional plan view taken along the line VI-VI of Fig. Y5; and

Fig. 7 is azvew similar to Fig. 6 Vshowing the finishing of a master cam.

Referring now to the vdrawings for a better understanding or" our invention, our improved apparatus vembodies end members 'lil and Il joined together by a .base member l2. Continuous grooves I3 and it extend longitudinally of the base member and adapt it for mounting upon the ways it of the lathe indicated generally by the numeral V. VThe end frame members l] and H have relatively large openings 't8 land l respectively therein through which passes a master Vcam shaft 2l, the openings being wide enoughfto permit a relatively wide swinging movement of the shaft. The master camshaft 2| is removably journalled in the lower endsof varm-s 22 and'23 whichV depend from an upper lhousing 24,'mounted on a shaft y255, supportedin the'end members It and H. The master cam shaft 2l is driven from the head stock 2l of the lathe through a shaft 28 and universal coupling 29. As shown in Fig. fi of the dra-wing, it is ycontemplated that a plurality of master cams 3l willbe carried on the master cam shaft to control the cutting-of Vcani blanks as hereinafter explained. On the lower end-of each of the ydepending arms '22 and 23 `is a bracket 32, each having a hole 33 drilled `therethrough at an angle, as shown in Fig. 1 to receive one 'end of a spring Sli, which spring may be quickly yattached to the brackets by passing pins V(i6 through theeyes of the springs ias kshown 'in Fig. l. The 'other yend of each'spring '3'4 is con 3 nected, as shown at 3|, to its associated end member. A small bracket 38 is mounted on the end member and has mounted therein a limiting set screw 39 which is disposed in position to engage the depending arm 22 and limit the swinging movement thereof responsive to the springs 34.

On the outer end of the master cam shaft 2| is a spindle 4| upon which may be mounted a model cam 42 as shown in Figs. 5 and 6, for laying out a master cam 3|, or which may receive a cam blank 43 for cutting to the desired contour as shown in Fig. 4 of the drawings. The spindle 4| is provided with a collar 44 having positioning pins 45 and 46 thereon by reference to which a model cam, or cam blank, may be positioned on the spindle 4| as hereafter explained.

Mounted in the end members and I at one side thereof is a guide shaft 41 upon which is slidably mounted a U-shaped selector arm 48. The arm 48 extends over the frame and housing 24 and downwardly on the opposite side of the machine. A bracket 49 is carried by the selector arm and extends inwardly thereof as shown particularly in Figs. 5, 6 and '7. The bracket 49 is adapted to have mounted therein a disk for scribing a master cam, as shown in Figs. 5 and 6, or it may have mounted thereon a grinding wheel 52 for grinding a master cam, as shown in Fig. 7 of the drawing. When cutting a cam blank as shown in Fig. 4 of the drawing, a roller 53 is mounted thereon to bear against a master cam 3 l, as shown in Figs. l and 4.

When the grinding wheel 52 is mounted in the bracket 49, as shown in Fig. 7, it is driven from any suitable power source, not shown, by means of a shaft 55 which extends through the end member I0, the latter being provided with a bearing 51 for the shaft.

Extending longitudinally of the apparatus, on the side opposite the bracket 49, is a plate 58 which is joined to the end members |8 and Joined to the plate 58 and extending upwardly therefrom is a selector plate 59 in front of which the lower, free end of the selector arm 48 depends. The selector plate 59 is provided with a plurality of vertically extending, spaced grooves 6| having holes 62 at the lower ends thereof which extend through the plate 59. rl`he upper ends of the grooves 6| join a common groove 63 which extends longitudinally of the plate. Each of the grooves 8| and holes 62 is positioned opposite one of the master cams 3|. The lower end of the selector arm 43 has mounted therein a pin 64 which is disposed within a housing 66 having a spring B7 therein which bears against a shoulder B8 on the pin to bias it inwardly as shown in Fig. 1 of the drawings. The pin may be retracted by means of a handle 69. It will be seen that by placing the pin 64 in one of the holes 62 the bracket 49 will be positioned to cooperate with one of the master cams 3|. Whenever it is desired to move the selector arm to cooperate with a different master cam, the pin 64 is retracted sufficiently to clear the hole 62 and the arm 48 raised with the pin 64 bearing in the bottom of the associated groove 6|. The arm is then rotated, or lifted, upwardly with the pin 64 in the groove 6| until it reaches the groove 63. It may then be slid longitudinally of the machine to the selected groove 6| and then lowered until the pin 64 is again seated in the selected hole 62. When raising the arm 48, the limit screw 39, bearing against the arm 22 permits the roller 53 to be disengaged from the master cams and moved longitudinally. This provides a ready means for 4 positioning the selector arm with respect to the master cams.

At 1| in Fig. 4 is shown the usual tool post for the lathe having a. manually operated feed screw 12 and a manually operated screw 13 for raising the tool '|4. 'I'he tool post is employed in my improved apparatus to hold either a cutting tool 'I4 as shown in Fig. 4 or a feeler |6 as shown in Figs. 5, 6 and 7.

The operation of our improved machine in reproducing cams from a model is as follows. One or more blanks which later become the master cams 3| are rst placed on the master cam shaft 2|. The springs 34 are disconnected from the brackets 32 so that the depending arms 22 and 23 hang vertically. The shaft 2| is turned manually and the pins 45 and 46 are positioned to lie in a horizontal plane by means of a level. A model cam 42 is then positioned on the shaft extension 4| by reference to a mark 'il on the end member A scribing disk 5| is then mounted in the bracket 49 and the selector arm 48 and bracket moved until the disk 5| is in Contact with the side of the selected cam blank 3|, as shown in Figs. 5 and 6. The cam blank 3| is secured to the master cam shaft 2| by means of dowels 'I8 which enter the shaft and which insure that the blank may be removed and replaced in the same position when desired. A feeler tool, preferably a pointed tool 76, as shown in Figs. 5 and 6, is placed in the tool post 1| to bear against the model cam 42. The shaft 2| is then rotated manually with the model cam bearing against the pointed feeler 16, and frequent stops are made to scribe lines, as shown in Fig. 5 on the side of the cam blank. By this means, the rough outline of the master cam is obtained. The master cam blank is then removed from the shaft 2| and the master cam may be cut by any suitable tool to the rough outline scribed as shown in Fig. 5.

When the master cam 3| has been roughed out, it is again mounted on the master cam shaft 2| in the same position as before The scribing disk l is removed from the bracket 49 and a grinding wheel 52 is mounted in the place thereof and is driven from the shaft 56 as heretofore explained by any suitable means, not shown. The model cam is held lightly in engagement with the feeler by manual pressure against the swinging frame. The master cam shaft is then connected to the shaft 28 and coupling 29, and is rotated with the feeler 16 bearing against the model cam 42. The master cam 3| is thus ground to a finished surface with an outline which is an intaglio reproduction of the surface of the model cam 42. When ground to the proper outline, the master cam is finished.

When the master cam has been completed as described, the grinding wheel 52 is removed from the bracket 49 and a roller 53, shown in Fig. 1, is substituted therefor. The model cam 42 is removed from the shaft extension 4| and in its place is mounted a cam blank 43. The feeler tool 'i6 is removed from the tool post and in its place is mounted a cutting tool 14. The master cam shaft 2| is now rotated again from the head stock through the shaft 28 and the roller 53 bearing against the surface of the master cam 3| holds the cam blank 43 in engagement with the cutting tool 14. During this time the springs S4 are connected to the brackets 32 to hold the master cam 3| in engagement with the roller 53. It will be understood that for this purpose the cam blank 43 will be rough cast or formed to an approximation of the outline designed. The proper depth of cut for the tool 14 is determined by the operator of the machine by measurement and the cam thus produced is an accurate reproduction of the model cam 42.

As will be seen particularly in Figs. 1 and 5, the element carried by the bracket 49, whether feeler element or forming tool, is substantially diametrically opposed to the element carried by the tool post 'Il with reference to the swinging shaft 2 I. Inasmuch as the latter swings through a relatively small arc, this positioning of the feeler and forming tool compensates for the angularity of movement of the shaft 2| and insures accuracy of reproduction.

By the manner of operation described, it will be seen that a plurality of master cams having different convolutions maybe successively formed and mounted on the master cam shaft 2| by successively mounting the appropriate model cam 42 on the extension 4| and moving the selector arm 48 to the appropriate position. It will thus be seen that we have devised an improved cam forming machine which is simple and sturdy of construction, having few moving parts, and which is capable to reproduce cams accurately and expeditiously.

While we have shown our invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and we desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims What we claim is:

1. In a cam forming machine, a main frame, a swing frame pivotally mounted to hang downwardly in the main frame, a rotary shaft mounted in the lower portion of the swing frame, a master cam mounted on the shaft, a cam blank mounted on the shaft, a relatively stationary feeler element mounted on one side of the frame and bearing against the master cam, a spring biasing the swing frame toward the feeler element, a relatively stationary forming tool mounted on the opposite side of the frame from the feeler element in position to act upon the cam blank, said feeler element and said forming tool bearing respectively against the master cam and the cam blank on opposite sides of a horizontal diametral plane passing through the master cam shaft.

2. In a cam forming machine, a main frame, a swing frame pivotally mounted to hang downwardly in the main frame, a rotary shaft mounted in the lower portion of the swing frame, means to drive the shaft, a master cam mounted on the shaft, a cam blank mounted on the shaft, a relatively stationary feeler element mounted on one side of the frame and bearing against the master cam, a relatively stationary forming tool mounted on the opposite side of the frame from the feeler element in position to act upon the cam blank, and means for `biasing the swing frame toward the feeler element.

3. In a cam forming machine, a main frame, a swing frame pivotally mounted to hang downwardly in the main frame, a rotary shaft mounted in the lower portion of the swing frame, means to drive the shaft, a master cam mounted on the shaft, a cam blank mounted on the shaft, a relatively stationary feeler element mounted on one side of the frame and bearing against the master cam, a relatively stationary forming tool mounted on the opposite side of the frame from the feeler element in position to act upon the cam blank, and a spring connecting the swing frame to the main frame to hold the master cam in contact with the feeler element.

CLAYTON G. WRIGHT. GENE C. THOMAS.

REFERENCES CITED Turner Aug. 14, 1923 Nelson Feb. 27, 1940 FOREIGN PATENTS Country Date Austria Sept. 25, 1924 Number Number 

